Changes in Multimorbidity and Disability Among Race/Ethnic Older Adults: AD/ADRD-Focused Administrative Supplement Summary Dementia affects over 5 million older adults in the US, with vast implications for individual patients, their caregivers, and social programs designed to support increasing health care needs. Research to date has not fully clarified the role that multiple co-occurring chronic conditions (multimorbidity) play in the provision of appropriate care for racially and ethnically diverse groups of older adults with mild or more severe cognitive impairment. As a result, there is a need for greater understanding of the complex interactions between existing morbidity combinations, cognitive impairment, and the receipt of essential and appropriate care. As of yet, it is unclear whether specific multimorbidity combinations alongside cognitive impairment present greater difficulty in accessing good-quality, and appropriate care and preventive services among older adults from underrepresented racial/ethnic backgrounds. The supplement extends from the research conducted in the parent award by focusing on older adults with cognitive impairment or dementia and co-existing chronic conditions. The goal of this supplement is to evaluate racial and ethnic differences in the quality of care received for older adults with dementia and competing multimorbidity care demands. We propose to use existing databases and multimorbidity combinations and patterns recently found in the parent grant. Our proposed research employs data from over 20 years of nationally-representative biennial surveys (~38,000 sampled people in the Health & Retirement Study) linked to Medicare claims. We propose two aims: Aim 1. Determine racial and ethnic differences in receipt of preventive services among older adults with mild or severe cognitive impairment and various multimorbidity combinations. Aim 2. Evaluate racial and ethnic differences in potentially avoidable hospital admissions and emergency department (ED) visits with discharge among older adults with mild or severe cognitive impairment and various multimorbidity patterns.